Ou8thisSN Posted February 5, 2003 Share Posted February 5, 2003 Its a dumb question, but why are all "high tech" recievers' volume control numbered like that? like my Onkyo has marks at-60db and then at 0db and then at +18db. There is no explanation in the manual, maybe you all have solved the mystery. Does 0db the "reference level" or is it the level when the reciever is putting out its threshold wattage that its rated for? Also, how do you find out what the Dolby/THX/DTS reference levels are that different reviewers keep talking about? Quote Link to comment Share on other sites More sharing options...
dougdrake Posted February 5, 2003 Share Posted February 5, 2003 Not a dumb question. 0 is just an arbitrary number they assign to the volume range, roughly where they think it will generate the reference volumes needed for the DD/DTS formats. With my setup, I achieve those volumes at -10 on my Denon's volume scale. If you want, you can adjust your channel volumes so that 0 will generate the reference volumes, but I wouldn't suggest it. You'll have to set the channel levels down a long ways to make that happen. The levels should be defined at their respective web sites, http://www.dolby.com/digital/ and http://www.dtsonline.com/ and http://www.thx.com/. I believe it is 105db (115db for subwoofer) for DD/DTS. Keep in mind that most test CDs allow you to set your levels using their lowered test signals (at either 75db or 85db) so you don't melt your eardrums while calibrating. DD Quote Link to comment Share on other sites More sharing options...
Frzninvt Posted February 5, 2003 Share Posted February 5, 2003 Oh My God! -10 on your Denon receiver! Mine is loud at -40db and I can't imagine watching a DVD with the volume at -10 and certainly not 0 it would be louder than hell. I have had it to those levels with no one in the house or nearby and can tell you the sonic wave generated is intense. At that volume level it would be close or higher than 120db in the living room. Yikes! Of course I run powerful outboard amplifiers and this may be a factor. I would also guess that "0" is the reference level meaning nothing is added or subtracted from the input level. Essentially wide open. I would love to be able to watch at -10db it would certainly be intense! Quote Link to comment Share on other sites More sharing options...
Invidiosulus Posted February 5, 2003 Share Posted February 5, 2003 On my yamaha reciever I hit 110 dB on episode 2 with no subwoofer. The yammy was set at -24. Sheesh, that was plenty loud enough for me. btw, when I saw The Two Towers on opening night I took my spl meter with me and the level topped out(in the front row lined up with the sub) at about 97 dB. This was in the large DTS THX theater at downtown Disney. The film itself however was in DTS but was not mastered using the THX standards. Peace, Josh Quote Link to comment Share on other sites More sharing options...
Bruinsrme Posted February 5, 2003 Share Posted February 5, 2003 that was a very good question. I always understood the following -60 can't hear squat -40 can hear the important stuff -20 now were feeling it 0 ears are a ringing +20 gonna need hearing aid in a couple of years. But the real question is why not simply use a scale 0 to 100? Quote Link to comment Share on other sites More sharing options...
artto Posted February 5, 2003 Share Posted February 5, 2003 First lets clarify what a "volume" control is. Even though its commonly labeled & called a volume control, its not really a "volume" control. The proper term is actually "gain control". It controls the amount gain (or amplification FACTOR or ratio). For instance, 1 volt in, 2 volts out: 1 volt, in 3 volts out: etc. You can drive any amplifier to full output, & beyond, at any gain (volume) control setting given enough input as long as the amp tolerates the input levels. In your case, I suspect +18Db is the full potential "gain" of the amplifier. The 0Db level is probably what is called "unity gain", which is the point where the amplifier is not contributing any gain in & of itself (ie: 1 volt in, 1 volt out). Levels from -1Db to -60Db are probably actually "attenuation". In otherwords, at those gain settings, the level from the source (CD, radio, etc) is actually being reduced. Quote Link to comment Share on other sites More sharing options...
Gordon Groff Posted February 5, 2003 Share Posted February 5, 2003 In the digital recording world, 0 dB represents "full scale", in other words, all the bits are full. It's the loudest you can get. Any level recorded over this causes "clipping" - that produces a very nasty sound. When audio is mastered, engineers take the peaks (loudest parts) up close to 0 dB (-.3 is a good "max"). Music that seems louder than other music is usually "compressed" by lowering the peaks and then raising everything closer to 0 dB. This reduces dynamics and is used sparingly, if at all, with classical piano or orchestral music. For radio, most music is squashed pretty hard so you don't have much volume change throughout a song. In the good old days of analog recording, the engineer could go over 0dB and cause tape saturation, which was sometimes a good sound. I'm a little fuzzy on how this relates to amp outputs, but arrto has it nailed pretty good - 0dB represents Unity Gain, which is no attenuation or amplification of the signal. That's the Holy Grail level of sound engineers - to keep everything at unity gain through all the mic preamps, compressors, eq's, etc. in their input chain up to the recording or output device. I suppose technically, if you could adjust the gain of your power amp, the cleanest signal would be with your preamp volume control set at 0dB. This is not how it works though. Power amps like to be let full open and the preamp attenuates the signal to control the volume. I guess I'm rambling. What was the question again? Gordon Quote Link to comment Share on other sites More sharing options...
artto Posted February 5, 2003 Share Posted February 5, 2003 Some food for thought Gordon....... The power amp will ruthlessly amplify everything that came before it, including noise, hum & distortion. I realize many folks think their power amp sounds best wide-open. However, this usually results in an inferior signal to noise ratio as any noise from the preamp (& pre-preamp: ie: moving coil phono pickup) & sources, will be amplified along with the music signal. In my case, my power amps seem to like running with the gain control half way up (12 o'clock) so I've opted to leave the gain controls intact instead of removing them as many audiophiles do. Audio Research SP6C preamp Luxman MB3045 power amps Quote Link to comment Share on other sites More sharing options...
Gordon Groff Posted February 5, 2003 Share Posted February 5, 2003 ---------------- On 2/5/2003 4:58:46 PM artto wrote: Some food for thought Gordon....... The power amp will ruthlessly amplify everything that came before it, including noise, hum & distortion. I realize many folks think their power amp sounds best wide-open. However, this usually results in an inferior signal to noise ratio as any noise from the preamp (& pre-preamp: ie: moving coil phono pickup) & sources, will be amplified along with the music signal. In my case, my power amps seem to like running with the gain control half way up (12 o'clock) so I've opted to leave the gain controls intact instead of removing them as many audiophiles do. Audio Research SP6C preamp Luxman MB3045 power amps ---------------- Right on! Unfortunately, many power amps (my two Hafflers for instance) do not have any gain controls and neither do the power amps in integrated recievers (I have NO idea how they work anyway - sharing loads across channels??? freaky!) I run my self-powered near-field monitors at about 1/2 too. Gordon Quote Link to comment Share on other sites More sharing options...
Ou8thisSN Posted February 5, 2003 Author Share Posted February 5, 2003 okay, I kind of understand what you guys are talking about but I want to know this. Does this mean that when I listen to something, at, lets say -15db, my amplifier is sending more power to drive the speakers, than if I were listening at 0db? the reason why i'm thinking this is the post that said 0db= 1 volt in, 1 volt out. Also, how does 0db translate into watts used. You guys are referring to volts and such, but everything is rated in watts per channel. So how does that translate to 0db? does that mean if an amplifer is rated as 100wpc with .05%THD at 8ohms or something, that this measurement is taken at the 0db mark on the amp? Basically, is 0db the optimal listening position, just like "tone defeat" ? Quote Link to comment Share on other sites More sharing options...
dougdrake Posted February 5, 2003 Share Posted February 5, 2003 Oh, yeah. Forgot about the attenuation/gain thing probably occurring at the 0 point. Ooops! Frnzn - Yeah, hard to compare with the outboard amplification. I'm using an Acurus 200x3 amp on my front channels. I'd have to suspect, though, that getting reference volumes at -40 puts you somewhat in the minority!! Wonder if room size affects that - maybe some "compression" going on. I've got all my gear stuffed in a little 11x10 room. Seems when it was in my living room with the vaulted ceilings, which opened onto 2 other rooms, it was louder at any given volume setting than it is in the small room. DD Quote Link to comment Share on other sites More sharing options...
artto Posted February 5, 2003 Share Posted February 5, 2003 Ou8, re:Does this mean that when I listen to something, at, lets say -15db, my amplifier is sending more power to drive the speakers, than if I were listening at 0db? No. Assuming the level marked 0Db is an indicator of "unity gain", that would mean that, at that level, your amplifier is passing the signal thru at the same level as if you took the CD player (for instance) & plugged it directly into the power amp (stage). Obviously, you can't do that with most receivers (unless it has a line level out like a preamp does). At the -15Db level you would be attenuating the input signal from the CD player (for instance) by 15Db. The gain (volume) control is a "relative" thing. It adjusts GAIN, not volume. It is not related to a specific output wattage. It controls the amount of INPUT. re:how does 0db translate into watts used. It doesn't. You could have your amp's volume control at "0Db" & still drive the amp past its rated power, IF, you have enough input signal. re:does that mean if an amplifer is rated as 100wpc with .05%THD at 8ohms or something, that this measurement is taken at the 0db mark on the amp? No again. If you look up the specs on the amp there is usually something called "input sensitivity" which will specify the amount of input voltage required for the amp to achieve a specified or rated output in watts with a specific load (resistance or impedance). Such as 0.75 volts +-2% at 30watts at 8 ohms. Under this condition, 0.25 volts in would cause the amp to produce 1/3 of its rated output, or 10 watts out. It doesn't have anything to do with the numbers on the volume control. The volume, or gain control, simply increases or decreases the level of the INPUT SIGNAL. The 0Db mark is simply the unity gain point. Unity gain is often used as a reference point for recording & sound engineers to achieve the best signal to noise ratio between various components. Some amps sound best operated that way, some don't. If you vary the gain levels between a preamp & power amp you can often affect the "tonal balance" of the setup. IE: preamp turned down low, power amp high, or vice versa. Its all basically a balancing act to get the best tone, lowest noise & achieve the desired gain with the speakers you are using & the conditions under which they are being used/listened to. Volts x amps = watts. Different amps achieve this differently. It all depends on the design. 3Db = doubling of power from the previous level. -3Db = one-half the power. It takes roughly 10Db increase in sound level to make something sound twice as loud to the human ear. If you have no way of measuring the input signal & without knowing the input sensitivity of the amp, you really don't know how much power the amp is putting out unless your amp has calibrated power output indicators or you use a sound pressure level meter, know the efficiency rating of your speakers, & calculate the power based on the sound pressure level the speakers are producing. The room's acoustics can affect measurements of this sort. Quote Link to comment Share on other sites More sharing options...
Gordon Groff Posted February 5, 2003 Share Posted February 5, 2003 Good answer arrto! For most practical purposes for most of us (myself included), the volume control on your preamp could indicate 1-10 instead of being rated in dB for all the difference it would make. I love the idea, though, of adjusting the power amps to a comfortable listening level w/the preamp at 0dB. That should (theoretically, depending on, well, lots of stuff!) give the best sound. If you can control your power amp output seperately, playing with relavtive levels is a very cool idea! Gordon Quote Link to comment Share on other sites More sharing options...
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